New markets for MAN CNG buses

New markets for MAN CNG buses

New family of right-hand-drive vehicles for the UK market

Market launch of MAN Lion's City CNG in Russia

Natural gas as a particularly clean source of energy for buses has been established in a large number of markets all over the world for many years now. MAN's experience with CNG buses is one that can be measured in decades and in millions of kilometres. The UK and Russia are new CNG-relevant markets and both are currently showing great interest: it can be foreseen that natural-gas technology will in future be employed to a far greater extent than has been the case so far. In the oil-producing countries of the Middle East too, the natural-gas deposits existing there are being utilised increasingly as fuel for vehicles. For all these markets, MAN Truck & Bus offers natural-gas-powered buses with just the right product characteristics.

MAN EcoCity family launches in the UK

The right-hand-drive market UK is displaying a lot of interest in propulsion systems for city buses that reduce CO2 emissions. After successful market tests, MAN, in cooperation with the Portuguese body builder Caetano, has developed a right-hand-drive vehicle adapted exactly to this market: the MAN EcoCity. The family's first model, the low-floor variant, has been on the market since November 2011. At the moment, two demonstration vehicles are in regular service, one in Reading, west of London, and one in Oxford. Demonstration service with further major bus operators during the coming months has already been planned. MAN is adding a low-entry variant to the EcoCity range timed to coincide with the BusDays in March 2012.

The drive train is equipped with the tried and trusted MAN E2876 EEV-compliant engine, whose 12.8-litre capacity and 272 hp offers superb propulsion for the 12-metre bus with its 40 seats (plus two tip-ups). Four gas tanks with a capacity of 1,176 litres provide the necessary range. Automated gearboxes from ZF and Voith, both with integrated retarder, ensure that force is efficiently transmitted to the road. The body is a weight-reducing aluminium construction with specially developed C-profiles and aluminium cladding. A steel framework reinforces the front and rear of the body, which is certified in accordance with ECE 66 safety standards. The modular construction of the body makes it straightforward to realise the bus in different lengths. The passenger compartment is illuminated with energy-saving LEDs and has bonded glazing. This gives the MAN EcoCity a bright, spacious feeling.

Given the cost of energy in the UK, operating a CNG bus pays for itself in a short space of time: operating costs are around 30 percent lower than for a diesel bus. Reliability is a major factor for municipalities when investments are planned. In this regard, CNG buses from MAN offer a high level of security for the future. By contrast with the prices of other fuels, gas prices are so stable that energy suppliers can enter into five-year fixed-price contracts.

The development of a natural-gas supply plays an important role in the UK market. The "Gas Bus Alliance" (GBA) consortium specialises in developing the gas infrastructure for bus operators and thus in promoting the spread of automobile gas filling stations. GBA installs the tank unit and gas-processing system on site, typically on the bus operator's premises, and will also take over financing, operation and maintenance if requested. Gas-processing is a key factor in achieving one-hundred-percent operational safety, because gas in the UK varies in quality and the proportion of biogas fed into the network is rapidly increasing. The increase in biogas also means that operators can reduce their CO2 emissions considerably.

In October and November 2011, Russians experienced the market launch of the MAN Lion's City CNG in an unusual setting: on the "Blue Corridor 2011", a rally of more than 3,570 kilometres through 11 Russian cities and over the Urals, the MAN Lion's City CNG low-floor bus was demonstrating the reliability of natural-gas technology in this class of vehicle. Russia is predestined to become a market for natural-gas-powered vehicles as it has enormous gas deposits; approximately half the country's primary energy demand is met by this source.

There are currently around 90,000 gas-powered vehicles operating in Russia as a whole, including buses, trucks and passenger vehicles. The Russian Federation boasts some 250 CNG filling stations. The Blue Corridor rally, starting in Yekaterinburg and finishing in Moscow, was started with the idea of popularising natural gas as an environmentally friendly, economical fuel for motor vehicles. The network of filling stations will be expanded accordingly and cities are showing great interest in CNG buses: after its arrival in Moscow, the bus was handed over by MAN to the West Siberian city of Tomsk (population 500,000) for field tests. Climatic conditions there are harsh, with temperatures in winter dropping to -40° Celsius.

MAN Lion's City CNG version for hot countries

Many oil-producing countries in the Middle East are developing into markets for CNG buses. The gas generated in the extraction of crude oil is being increasingly exploited and used as fuel. For this reason, MAN offers the Lion's City CNG in a version designed especially for very hot countries.

The bright, friendly interior of the Lion's City is kept at a temperature that passengers experience as pleasant by a tropical air-conditioning system delivering a maximum of 44 kW cooling performance. Air curtains on the doors prevent the hot outside air getting in when passengers board and alight at the bus stops – this system has already proven itself on the more than 800 buses from MAN Truck & Bus operating in regular service in Dubai and Abu Dhabi.

This version is driven by a turbocharged six-cylinder engine powered by natural gas and delivering 228 kW (310 hp) with emissions way below the limits set for EEV, currently the most stringent emission standard. The engine's exhaust gases are especially low in nitrogen oxides (NOx) and particulates. Applications for hot countries such as a pre-separator for the air-intake system ensure reliable operation in very dusty regions where temperatures are high. Power from the natural-gas engine is transmitted to the driving axle by means of an automatic six-speed gearbox equipped with intarder. The gearbox software detects up- and downhill gradients, automatically adjusting the gearshift points as it does so. This reduces fuel consumption.

The natural gas is carried in a total of eight aluminium composite cylinders (rated for a pressure of 200 bar), each with a volume of 214 litres or 1,712 litres in all. The gas cylinders are stored under the attractively designed roof fairing, which can be folded open on both sides, making for good accessibility. Storage volume is calculated on the basis of typical inner-city demand, so that the uncomplicated refill procedure can be carried out at the depot in the evening or at night. Alternative packages of cylinders are available on request.

The world's assured accessible natural-gas reserves are estimated at almost 190 billion cubic metres - at today's rate of extraction that's enough for the next sixty years. If one adds the natural-gas resources (meaning gas that cannot yet be extracted or only with great effort), then the range is around 130 years. At more than 75 billion cubic metres, the world's biggest deposits of natural gas have been found in the Near and Middle East, followed by Eastern Europe / CIS (62 billion), North, Central and South America (17), Far East/Pacific (15) and Africa (14). Security of supply and combustion characteristics are factors in favour of natural gas as an alternative source of energy for both stationary and mobile applications - this is being recognised by more and more countries around the world. This is why the UAE, for example, decided years ago that natural gas was to account for twenty percent of the total amount of fuel consumed on its roads by the year 2012.

Natural gas is an eco-friendly source of primary energy. Extracting, cleaning and transporting the fossil fuel with the lowest carbon content require comparatively little energy. The specific emission of greenhouse gases by natural gas - calculated for the entire chain of supply, i.e. from the well to the tank - is around 65 grams per megajoule of energy, which makes it almost a quarter less than that of diesel. Although this advantage is to a certain extent cancelled out by the lower efficiency of the natural-gas powered engine relative to the diesel engine as well as by the additional weight of the fuel storage, natural gas still boasts the highest CO2 efficiency of all fossil fuels in the "well-to-wheel" comparison.

With the help of bio-natural-gas, the operation of CNG buses can be very nearly CO2 neutral. The biogas resulting from the fermentation of organic substances such as green waste, leftover food or liquid manure is upgraded by means of a special procedure to the quality of natural gas, after which it combusts cleanly and unproblematically in series-produced natural-gas engines without the need for any further technical modifications.

A characteristic of natural gas is that it burns very cleanly by comparison with other fossil fuels, so that gas-powered engines emit low levels of air pollutants such as carbon monoxide (50% less than diesel), hydrocarbons (80% less), nitrogen oxides (70% less) and particulate matter (up to 99% less than a diesel engine without a particulate filter). MAN's natural-gas-powered buses use this to their advantage and have for several years - and without complex exhaust-gas treatment systems - already been considerably within the limits laid down by the EEV (Enhanced Environmentally-friendly Vehicle) standard, currently the most stringent in the EU. CNG buses also tend to be quieter than their diesel-powered compatriots, thanks to the fact that natural gas is combusted in SI engines.

The many years of experience with CNG-powered drives are paying off

MAN Truck & Bus can point to the experience of a quarter of a century in natural-gas-powered buses: as far back as 1972, MAN buses with gas-powered engines were shuttling Olympic athletes and spectators to the stadiums in Munich and its environs. Twenty years later, the MAN SL 202 with CNG-powered engine celebrated its premiere and in 2003, MAN delivered the first EEV-compliant gas-powered buses to its customers. In the meantime, MAN has delivered more than 5,000 gas-powered buses and bus chassis with gas-powered engines. Major markets for these buses and engines are The Netherlands, Turkey, Germany, Sweden, Australia, Austria, Portugal, Iran and Spain. MAN's share of the European market for these buses has averaged 44 percent over the past eight years. In fact, from 2007 to 2009, MAN's share was over half the market.

This success is based solidly on MAN's modern natural-gas-powered engines. There are currently two series of engines (E08 and E28) available for bus and bus-chassis applications in five output classes from 162 kW (220 hp) to 228 kW (310 hp). The MAN E0836 LOH 01 natural-gas engine with a capacity of 6.9 litres and turbocharging is available in three output classes; 162 kW (220 hp), 184 kW (250 hp) and 206 kW (280 hp). In each case, this output is delivered at 2,200 rpm. Thanks to its excellent power-to-weight ratio - dry, the engine weighs a mere 650 kilograms - the E08 engine is particularly suitable for buses operating largely in flat regions or for installation in compact (midi) buses. At the moment MAN is offering this engine exclusively to external bus manufacturers.

Where more power and torque are required, the 12.8-litre OBD2-enabled MAN E2876 LUH natural-gas-powered turbocharged engine is called for. This engine is available in two output classes, 200 and 228 kW (272 and 310 hp) and is the standard engine in MAN's natural-gas powered buses.

The range of natural-gas engines that comprehensively covers the power spectrum is paralleled by MAN's range of complete buses which admits no compromise: Natural-gas-powered drives can be ordered as alternatives for just about every model in the new generation of Lion's City modern, low-floor city buses as well as the latest derivation, the new low-entry variant - from the 12-metre long solo bus to the 18.75-metre long articulated bus. For individual adaptation of the fuel storage to the required range of the vehicle there is a comprehensive selection of roof storage modules to choose from. Starting with a standardised aluminium frame, between six and ten gas cylinders can be arranged under the harmoniously designed roof fairing. There is a choice of various types of cylinder for storing the gas, so that almost any wish in terms of individual range can be fulfilled. Of course, MAN's city-bus chassis, renowned for being easy to build on, are also available with gas-powered engines.

The enormous experience MAN has had with gas-powered buses benefits the customer not only when it comes to getting advice on purchasing, but also in the planning and development of the fuel and service infrastructure. It goes without saying that MAN Service is completely familiar with the maintenance and repair of the high-pressure gas systems and that the global supply of spare parts for gas-powered buses is assured. If the customer requests it, training courses will ensure that MAN's know-how is competently transferred to the customer's own service personnel or an external service team. This ensures the smooth operation of the gas-powered buses made by MAN.

Moreover, natural gas is an economical alternative for public transport companies: in many countries, gas is cheaper than diesel, in addition to which operators of gas-powered buses can often profit from state-funded incentives aimed at increasing the percentage of natural gas in the fuel mix.

Finally, natural gas pioneers the way towards a later move to a supply system for gaseous, regeneratively-produced fuels such as synthetic gas or hydrogen.